[Elecraft] KLPA3A power transistor thermal stress concerns

[Rose]

Nick,

What is the "12 watt" version you're referring to?

73

K0PP

On Oct 24, 2017 5:29 AM, "Nick - VE3EY" <nick.ve3ey at gmail.com> wrote:

> I have a K3s/10 (12 watt version) which I intend to use in the upcoming cq
> ww cw contest.  This unit does not have KPA3A power brick and cooling fans
> installed.
>
> While doing some trial runs I noticed that the area around the KLPA3A power
> transistors is getting fairly hot after prolonged contest use.  My guess is
> the transistors are working harder when used as finals.  The rig needs to
> produce between 6 and 12 watts to properly drive the SS amp I intend to
> use.
>
> Looking for some opinions:
>
> 1.  Don't worry about it.  I am paranoid.  The KLPA3A power transistors can
> sustain the rigor of 40+ hours use in the contest.  Just make sure they are
> properly fastened as directed in the assembly manual.
>
> 2.  Rig up some passive thermal cooling.   Perhaps a heat-sink underneath
> the rig to allow heat to dissipate.
>
> 3.  Mount a 12v cooling fan somewhere to allow for airflow underneath the
> radio to take away excess heat.
>
>
>
> 73
>
> Nick VE3EY
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